Self-blowout or self-extinguishing circuit breakers (also called gas-blast circuit breakers) are used, for example, in high-voltage technology. Self-blowout circuit breakers are designed in such a manner that, in the event of the contacts being disconnected or in the event of a short circuit, a resultant arc is blasted with a gas and is thereby quenched as quickly as possible. The most widely used gas for this purpose is SF6 (sulfur hexafluoride).
European patent application EP 1939910 A1 discloses a gas-blast circuit breaker having a plurality of contacts which can be moved relative to one another. A blowing volume which is connected to an arc zone via a blowing channel is arranged around a first contact. The blowing volume is separated from a low-pressure space by a separating element. A throughflow opening which is used to exchange gas between the blowing volume and the low-pressure space is provided in the separating element.
U.S. Pat. No. 5,589,673 discloses a self-blowout circuit breaker in which a pressure chamber, in which the arc is produced, is connected under the control of a valve to a compression space. The compression space is connected to a low-pressure space via an overpressure valve and a top-up valve or filling valve. The valves are annular and are arranged such that they rest against one another with an overlapping zone. On the side of the low-pressure space, the overpressure valve is pressed against a valve holder in the direction of the compression volume by a spring. Gas can therefore flow from the compression volume into the low-pressure space only when its pressure is greater than the spring force. This design is relatively complicated and involves a large number of elements.